Nutrition and management of ewes before and after lambing

D.C. Smeaton, P.V. Rattray, B. Mackisack, S. Heath and H-U.P. Hockey

Whatawhata Hill Country Research Centre, Ministry of Agriculture and Fisheries, Hamilton and Ruakura Animal Research Station, Ministry of Agriculture and Fisheries, Hamilton

Proceedings of the New Zealand Society of Animal Production. 1983, 43: 37-40

In Trial 1, ewes were fed high or low nutrition in mid and late pregnancy and post lambing until docking in a 2ł factorial. Pasture residue levels for the high and low nutrition groups were 1000, 250; 800, 300; 600, 450 kg DM/ha for the 3 periods respectively. The ewes were rotationally grazed before lambing and then set stocked at 12 and 20 ewes/ha. In a second trial, ewes were rotationally grazed until 4 weeks before lambing, stocked at 12 and 20 ewes/ha, and either set stocked immediately or at lambing, until weaning.

There were no effects on lambing percentage or on ewe and lamb survival. Level of GGT in Trial 1 affected live weight (-0.004 kg live weight/IU of GGT). After the mid pregnancy treatment the ewes weighed 56.3 and 44.1 kg and were still 2.9 kg different at docking. The mid, late pregnancy and post lambing treatments affected ewe live weight as a 3- factor interaction. Mid and late pregnancy nutrition affected birth weight but only mid pregnancy and (mainly) post lambing nutrition affected lamb docking and weaning weight.

In Trial 2, ewes set stocked 4 weeks before lambing had consumed all their pasture (saved by their previous long rotation) by lambing compared with the other management group at 20 ewes/ha only and consequently they were +3.0, -1.1 and -2.6 kg different at lambing, docking and weaning respectively. Management affected lamb weight at 20 ewes/ha only at docking but by weaning, set stocking ewes 4 weeks before lambing gave a main effect disadvantage of 1.9 kg compared to the other group, at both stocking rates.

Keywords: NZSAPAB; Nutrition; pasture residual; ewes; lambs; pregnancy; lambing; live weight; weaning; survival

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Last Updated 03-05-1997